Cooling fluid circulation in an annular disc brake

Abstract

Fluid passages machined in the annular brake piston and in the outboard brake ring of a wet disc brake system allows the circulation of cooling and lubricating fluid. An annular disc brake will deliver cooling fluid to the circumferential periphery of the brake disc operating cavity where the fluid relief passages machined in the annular brake piston and in the outboard brake ring will allow the passage of this fluid out of the brake disc operation cavity thus preventing the stagnation of cooling fluid in the brake disc operating cavity.

What is claimed is: 
     
       1. A disc brake operating in a fluid environment comprising: a housing, including a brake disc operating cavity including an annular fluid passage;   a reservoir source of fluid contained in said housing;   a rotatable shaft carried in said housing;   a brake disc including radial braking surfaces slideably carried on said rotatable shaft for rotation therewith, said brake disc partially submerged in said reservoir source of fluid, said brake disc having means to pump said fluid by centrifugal force from the radial surfaces of said brake disc to said annular fluid passage said annular fluid passage being located immediately circumferential to the outer periphery of the brake disc;   an inboard brake ring having flat surfaces on both sides thereof carried in said housing circumferentially disposed around said rotatable shaft, said inboard brake ring being adjacent said brake disc;   an annular piston carried in said housing circumferentially disposed with respect to said rotatable shaft, said annular piston having a plurality of communication notches for allowing fluid to pass from said annular fluid passage to said reservoir source of fluid and a circumferential annular channel formed in the outboard face thereof, said outboard face of said annular piston being adjacent said inboard brake ring;   an outboard brake ring adjacent said brake disc on the side opposite said inboard brake ring, fixedly mounted in said housing circumferentially disposed around said rotatable shaft, said outboard brake ring having a flat surface adjacent said brake disc and a contoured surface having a plurality of force transmission surfaces engaging said housing, a plurality of fluid access channels for allowing fluid to pass from said annular fluid passage to said reservoir source of fluid and an annular depression therein;   whereby said communication notches in said annular piston and said fluid access channels in said outboard brake ring provide egress for fluid pumped into said annular fluid passage of said housing by said brake disc thereby allowing circulation of cooling fluid past said brake disc.   
     
     
       2. The invention in accordance with claim 1 wherein said brake disc comprises: a flat disc having a plurality of apertures therethrough including a central splined aperture and radially disposed apertures;   lining material affixed to the outer area of both major planar surfaces of said disc;   fluid baffle rings affixed to the central area of both planar surfaces partially covering said radially disposed apertures of said flat disc.   
     
     
       3. The invention in accordance with claim 1 wherein said fluid will be evacuated from said annular fluid passage into secondary fluid passages in said housing, said secondary fluid passages including clearance (76), open zone (80) and inboard passage (78). 
     
     
       4. The invention in accordance with claim 3 wherein said fluid may pass from said clearance (76), through said fluid access channel (66) to the bearing assembly (82).